Airborne Sonar Systems have been in use for a number of years in which an aircraft, such as a helicopter which has a capability of hovering over a particular location, carries a sonar system including a reeling mechanism, a cable and a transducer which is reeled into the water and retrieved as needed. While in the water, the transducer radiates a desired sonar echo ranging signal, and hydrophone assemblies forming part of the transducer receive any echo signals resulting from such radiation. These signals are then processed and appear on a readout device in the helicopter itself, thereby enabling the operator to determine the direction and range of the reflecting object. In order to avoid having transducers of excessive size and weight, the operating frequency of such systems is usually fairly high, such as of the order of 10Khz. Because of the use of the comparatively high frequency, the operating range of such sonar systems is limited. For some time it has been desired to combine such a system with means capable of providing a listening function capable of picking up signals from a much longer range. Such a limiting device would inherently operate at substantially lower frequencies, of the order of a few hundred Hz. Attempts to add such a listening hydrophone to the conventional airborne sonar system have encountered some severe problems, one of the most formidable of which is that when the low frequency hydrophone is attached to the housing of the airborne sonar transducer, it has imparted to it all of the vibration, hence noise, introduced down the cable from the aircraft engine itself, noise from the rotor, and other extraneous mechanical and electrical noise which is translated into the transducer housing and much of which occurs in the low frequency range at which such a hydrophone would operate. The desired low frequency sonar signals reaching the hydrophone from a substantial distance would necessarily be of comparatively small magnitudes so that they are easily covered up or distorted by the various signals emanating from the aircraft. Some of those working in the field have theorized that if such a low frequency hydrophone could be mounted on the transducer in such manner that it is comparatively unresponsive to the aircraft noise and other interference referred to above that this might solve the problem of introducing such noise into the electrical output of the hydrophone. A highly compliant mounting means for the hydrophone capable of eliminating such noise, however, would create serious problems in assembly and handling of the combined transducer structure. Most of the obvious caging arrangements for such a mounting means would require manual or electrical uncaging or releasing means or manual operations which introduce problems of their own.